Spark plug



J. B. ROGERS.

SPARK PLUG.

APPLICATION FILED JUNE 17, 1918.

Patented Mar. 28, 1922.

' narran stares JAMES B. ROGERS, 0F CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO L,

YOIE CHICAGO, ILLINOIS.

s. POWELL,

SPARK PLUG.

igricyes.

To all whom 2'?? may concern.'

Be it known that I, JAMES B. ROGERS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Spark Plugs, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

`My invention relates to improvements in spark plugs, one of the objects "of myinvention being to provide a non-fouling spark plug. To this end I so construct my plug that only a small portion of the compressed gas of the explosive engine is first ignited in a confined space, whereby intense heat is deve-loped about the electrodes of the plug and all carbon and products of combustion are entirely consumed, so that the electrodes of the plug always remain clean.

Forthe purpose of disclosing my invene tion I have illustrated' one embodiment thereof inthe accompanyingdrawings, in whichf Y Fig. 1 is a longitudinal sectional view of a spark plug embodying my invention;

Fig. 2 is a section taken on the line 2-2 of Fig. 1; j

Fig. 3 is anv elevation of the insulator of my plum,

Fig. 4 1s an elevation of the lower electrede and its support;

F 5 is a top plan view of the lower elec-v,

trode support;

Fig. 6 is a perspective View of the upper electrode; and v ig. 7 is a sectional view of the modified form of body of my spark plug.

In the embodiment of my invention illustrated, I provide a body 1 externally screwthreaded, as at 2, to screw into the engine cylinder. This body has aV central chamber 3, which is a portion of the hollow core eX- tending through the body and the side walls of which are curved 'on an ellipse. The insulator Ltis shouldered, as at 5, to rest upon the top of the body -1, and has another shoulder 6 whichV is engaged by the gland -nut 7, through which the top 'of the insulator projects. The lower end of this gland nut is screw-threaded, asat 8, to engage on the screw-threads of the body, so that the insulator may be firmly clamped in position. Preferably an asbestos washer 9V is inter1n Specification of Letters Patent.

Patented Mar. 28, 15122. 240,301.

posed between the shoulder 5 and the top of the body, and a combined asbestos and copper washer is interposed between the gland nut and the shoulder on the insulator. rlhe insulator has Vextending centrally therethrough the conducting rod 10, on the lower end of which is mounted the forked electrode 11. This electrode is preferably formed of tungsten. and the upper part thereof is countersunk 1n a suitable recess 12 inthe insulator, sultable sealing matter being placed in the recess to formd an air-tight joint at this point. The lower end of the insulator is hollowed or cored out to form an explosion chamber 13, in whichis arranged the upper' electrode 11. f he sides; of this chambered portion of the insulator have suitable openings orports lutherein. The bottom electrode 15 `of the plug likewise has its upper end formed of tungsten and preferably takes the shape of a rod having an enlargement 16 formed thereon, which partially closes the bottom of the chamber formed in the insulator. The lower end of this rod is secured 1n and supported by a suitable support 17, which takes the'formfof a truncated washer 1n the form of aspider, the hub of which supports the bottom electrode and the rim of which is seated in the* bottom of the body. The lower portion of the body is milled out to form asuitable seat for the rim of the support. After the rim has been placed in position the annular ange 18 left by forming the seat for the rim is turned over, securely locking the support in position. VBy truncating the .spider support inthe manner illustrated, larger'openingsare formed for the passage of the gas. The lower electrode is extended so that it occupies a position between thc two forked ends of the upper electrode, so that the parts are always maintained in definite spacedrelation and the danger of the contacts` engaging by clamping the insulator' in position is eliminated. The upper end of the insulator, where the conductor rodl projects through, is recessed, as at 19, to receive a suitable filler to form at this point a gas-tight joint. The projecting end of the rod is provided with the usual nut 20 for attaching the conductor.

In Fig. 7 I have illustrated a modified form of body for my spark ,plug whereby means are provided for sighting the spark and also for priming, when desired. In this form of plug'the body l is provided i Vwhich is chamfered off, as at 22.

with an annular flange 2l, the side wall of hlounted upon the body above this flange is a second movable ring 23, which screws upon the threaded portion 24e of the body and has a chamfered face 25 co-operating with the face 22 of the ring 21. Extending through the ring and the side wall of the body is a port 24C. lt will be observed that by backing off the ring 23 until the port Q6 is eX- posed, a sight maybe taken through this port to ascertain if the sparking electrodes vare functioning properly; also, if desired, this port may be used for the purpose. of priming, bysintroducing a small quantity of gasoline through the port. When the spark plug is in use,k however, the ring 23 is screwed tightly down, so that the co-operating faces 25 and 22 fit Vtightly together, thereby closing' the port 26. Y

In the operation of my plug, a portion of the compressed charge ofthe cylinder enters the chamber in 'the bottom of the :insulator through the ports formed in the support 1'? and vthrough, the ports 14. As soon as the electrodes become activethe spark jumps from the tines 'of the upper electrode 1l to the lower electrode, thereby igniting the gas in the chamber. Due to the fact that the gas is confined in this chamber and has not the opportunity to rapidly expand, a veryintense heat is set up around the electrodes, which consumes all the products of combustion, and the electrodes, therefore, never become fouled. The chamber surrounding the electrodes becomes at the moment of ignition of the gas an arc furnace developing a very intense heat. The ignited gases pass out through the port 14 and through the openings in the Asupport 7 to ignite the charge in the engine, cylinder.

Having thus described my invention, what l claim as new and desire to secure by Letters Patent, is

l. In a spark plug, the combination with a body member adapted to be threaded into the wall of an engine cylinder, of an insulator Supported in said body and having a chamber at its lower end, sparking electrodes arranged in said chamber and Vsaid chamber having ports in the side walls thereof.

2. In a spark plug, the combination with a body vadapted to be threaded. into the wall of an engine cylinder, of an insulatormounted in said body having a 4chamber in its lower edge, a forked electrode arranged within said chamber and a second electrode having a portion thereof lying between the tines of theiirst electrode within said chamber, said chamber having ports yin the side walls thereof.

3.1n a spark plug, the combination with a body adapted to be screwed into an engine cylinder, of an insulator supported in mieres said body havin a chamber at its lower end, an upper anc lower electrode arranged in said chamber, and a support for the lower electrode comprising a truncated ported washer secured at the lower end of the body.

4;. ln a spark plug, the combination with a body adapted to be screwed into the cylinder of an engine, of an insulator co-operating with said body and having a chamber at its lower end, a forked `upper electrode arranged within said chamber, a lower electrode extending between the tines of said upper electrode, and a support for said lower electrode comprising a truncated spider having a rim heldin position in the body and supporting the electrode on its hub.

5. In a spark plug, the combination with a body, of an insulator having a chamber at its lower end proyided with ports entending through itsside walls, aforked electrede mounted .in the upper part of said chamber, ja lower electrode, means for substantially closing the lower pa-rt. of 4said chamber, and a support for said lower electrode comprising a truncatedv spider supporting the electrode at its hub and having a rim secured to the body. Y

6. ln a spark plug, the combination with a body adapted to be screwed into an engine cylinder, of anl insulator supported in said body and having a chamber formed in'its lower end vprovided with openings in the side walls thereof, the lower, end of said insulator having its side walls spaced apart from the walls of said body, and sparking electrodes arranged in said chamber.

7. ln a spark plug, the combination with a body adapted to be screwed into an engine cylinder, of -an insulator supported in said body and having a chamber formed inl its lower end provided with openingsin its side walls and being substantially closed at its bottom, theilower end of said insulator' having its side walls spaced apart from the walls of said body, land sparkingrelectrodes arranged in said chamber.

8. ln a spark plug, the combination with a body adapted to be screwed into a cylinder, of an insulator supported in said body and havinga chamber formed in its lower end provided with openings in the side walls thereof, the lower end of said i`nsulatoihaving its side walls spaced apart from the walls of saidbody, a sparkingelectiode sup# ported by said insulator andarranged within said chamber, a second sparking electrode supportedby said body extending into said chamber and having an enlargement sub-V stantially closing the lower end of said chamber. Y 1

9. In a spark plug, the combination with a body, of ali-,insulator mounted therein, an electrode supported b v said insulator and an electrode supported by saidbody, one of saidj electrodes having a forked portion within said insulator and the other having its end fitting between the tines of said fork.

10. In a spark plug, the combination with a body, of an insulator mounted therein, an electrode carried by said insulator, a second electrode carried by the body, a shoulder on the exterior of said body having a chamfered face, p said body having a priming opening extending therethrough, an opening on said chamered face, and a screw ring surrounding said body and having a chamfered face coinciding with the face of said shoulder. Y

l1. In a spark plug, the combination with a body having a chamber formed therein opening at the bottom, of an insulator having a chambered lower end arranged in said body chamber and provided with side openings in its walls, and electrodes arranged in said insulator chamber.

l2. In a spark plug, the combination with a body having a chamber formed therein opening at its bottom, of an insulator havingca chambered lower end arranged in said body chamber and provided with side openings in its wall and having its bottom substantially closed, and electrodes arranged in said insulator chamber.

In witness whereof, I have hereunto subscribed Iny name.

JAMES B. ROGERS. 

